For a half-dozen Washington area technology and computer services companies, 1976 was a year of mixed blessings. Profits rose at Scope, Inc., Ocean Data Systems, Multronics, Inc., and Vega Precision Laboratories but losses were reported by NUS Corp. and Tech Serv Inc.

Scope, a Reston manufacturer of communications, computer oriented systems and material handling products, reported profits of $2.1 million ($1.78 a share), a gain of 31 per cent from $1.6 million ($1.36) in 1975. Sales rose 19 per cent to $34 million.

William C. Schaub, Scope's president, attributed his firm's record results to an expansion of marketing in the U.S. and overseas.

NUS Corp., a Rockville energy and environmental consulting company, reported a net loss of $133,000 compared with profits in 1975 $704,000 (70 cents a share). Sales declined slightly to $24.4 million from $26.2 million.

A company spokesman said NUS suffered a fourth-quarter loss of $154,000 vs. profits of $123,000. The loss resulted primarily from settlement of two disputes over work performed in prior years and a reserve associated with the contemplated disposition of a small segment of the business.

Operating results for the year reflected "highly competitive" conditions which precluded rate increases necessary to recover costs in addition to "fluctuating workloads" in most operating units, NUS said. The backlog of contracts at year - end was $15.4 million compared with $9.4 million a year ealier.

Ocean Data Systems, a Rockville firm engaged in technical studies, systems design and computer programming in such areas as oceanography and weather information, reported profits of $271,415 ($2.16 a share) in the year ended last June 30, compared with $210,069 ($1.68) in the previous annual period.

Revenues rose to $4.7 million from $4.5 million. It was the sixth consecutive year of sales and earnings growth for Ocean Data, which had sales in 1971 of $734,739.

President Jerome Moreoff said recent developments indicate continued growth in the current year, including Motorala, Inc.'s selection of Ocean Data for a $2.7 million subcontract to supply a minicomputer-based information storage and display system for the Coast Guard's vessel control system in New York's harbor.

Tech Serv, a Beltsville manufacturer of electronic controls and research facilities for life science research and education, posted a loss of $138,000 for the six months ended Dec. 31 compared with a profit of $1,000. Sales felll to $833,000 from $957,000.

The company said continuing losses caused by weak sales are generating a "cash flow shortage" and "certain problems" in acquiring needed components for Tech Serv products. Orders in January and February were higher than in recent months but still below a level considered adequate.

Tech Serv said it reached a conclusion to a legal problem and that, as a result, the accounting firm of Arthur Young & Co. removed a qualification to the annual reports for fiscal years 1975 and 1976.

Vega Precision Laboratories, a Vienna radar engineering and manufacturing firm, reported 1976 profits of $284,169 (74 cents a share) compared with $122,383 (31 cents) in 1975. Sales rose from $5.5 million to $7.5 million. The Northern Virginia company reported a backlog of contracts of $8 million.

Multronics, Inc., a Columiba-based manufacturer of communications products, reported profits in the year ended Oct. 31 of $140,803 (15 cents a share) compared with $111,267 (12 cents) the previous year. Sales rose to $897,942 from $642,439.